1. Field
The disclosed embodiments relate to a compound-type wind power generator provided with a propeller wind turbine including a horizontal rotation shaft and a Magnus wind turbine including a perpendicular rotation shaft. It is herein to be noted that the term “perpendicular” is used with respect to the horizontal rotation shaft, and in other means, it may be called “vertical”.
2. Related Art
In conventional technology, there have been proposed various wind power generators, and as the most popular one, there is known a propeller wind power generator provided with a propeller wind turbine including a horizontal rotation shaft (for example, see Patent Document 1).
Generally, in such a propeller wind power generator, the generated power amount is proportional to the square of the radius of the propeller wind turbine and the cube of the wind velocity. Accordingly, the radius of the propeller wind turbine is increased to improve the power generation efficiency and profitability.
The wind velocity is lower near the ground because of friction due to ground-shape or obstacles, but at high altitudes, the wind is strong, and accordingly, the wind can be captured efficiently. Thus, the height of a column supporting the propeller wind turbine is increased.
It is generally desirable that the propeller wind turbine is installed at a windy place where the wind condition is favorable at any time of the year. However, in Japan which is a small country and has complex topography, the installation sites are limited, thus being inconvenient. Furthermore, there is a fear that ecosystems of birds and the like may be negatively affected by bird-strike or the like.
In recent years, a Magnus wind power generator provided with a Magnus wind turbine has been proposed (for example, see Patent Document 2). In a Magnus wind power generator, a plurality of rotation cylinders which rotate around perpendicular center shafts upon receipt of wind are radially arranged on a horizontal rotation shaft, and the rotation of the rotation cylinders around the perpendicular center shafts is converted into the horizontal rotation and transmitted to the horizontal rotation shaft by a transmitting mechanism, so that a generator is driven by the horizontal rotation shaft.
The Magnus wind turbine is generally small, and accordingly, the rotation cylinders can be rotated by relatively light wind.